Flying lower than launch height - Possible?

[Meta4]

Had switched off auto tracking and all by the time i started landing. The only extra step was updating the home point to the controller location. But still it started an auto land sequence pretty high up

Resetting the homepoint doesn't have any effect on the zero height that is established at power-up, or on landings.

If you post flight data, that might help pin down the issue.

 

[Izzikiorage]

Sharing the flight data, the issue would be just after the home point update and trying to land (towards end of flight)

Please help, this has been driving me crazy

 

[Meta4]

Sharing the flight data, the issue would be just after the home point update and trying to land (towards end of flight)

Please help, this has been driving me crazy

Here's what that flight data looks like:

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

The issue is caused by your VPS sensors.
They are working properly early in the flight, but from 5:29 they start to show false data.
Much of the time the VPS is, indicating that the drone is only 1-2 metres above whatever is below it.
When this happens, the drone won't descend properly to avoid crashing into the ground that's being falsely You neen to check the VPS sensors to ensure they are clean and that there is nothing blocking their downward view.

 

[Izzikiorage]

Here's what that flight data looks like:

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

The issue is caused by your VPS sensors.
They are working properly early in the flight, but from 5:29 they start to show false data.
Much of the time the VPS is, indicating that the drone is only 1-2 metres above whatever is below it.
When this happens, the drone won't descend properly to avoid crashing into the ground that's being falsely You neen to check the VPS sensors to ensure they are clean and that there is nothing blocking their downward view.

Thanka so much for sharing this, indeed even when the drone landed it seems like the sensor was assuming its 4ft and just before the confirmed landing sequence at 6 min the data says NA. Should i try cleaning it? There are no attachments of any kind that could block their view. Any specific things i should try and do to ensure this does not happen

 

[Izzikiorage]

Cleaned the sensors and did a quick check off a building roof. It did go below the launch height. Will try the active track thing again soon

 

[Meta4]

Cleaned the sensors and did a quick check off a building roof. It did go below the launch height.

The issue never had anything to do with the launch height.
It was that the VPS sensors were giving false data which slowed descent.

 

[tokertm]

Thank god there's now never an issue with flying below take off ... Back in 2010 or so on my walkera drone (yes I went that route B4 DJI), if you went below take off the props just stopped (Bad firmware, got patched but still happened from time to time)